Retinal dystropies have been studied in rats, mice, cats, and dogs. These examples of inherited retinal degenerations may be helpful in discovering the cause and/or treatment of human retinal diseases. In the proposed study, antibodies to retinoid-binding proteins will be used to study rat, mouse, dog, and human retinal degenerations. Retinoid-binding proteins are thought to be involved in physiological transfer of various forms of vitamin A inter- and intracellularly in retina and retinal pigment epithelium. Using immunocytochemical and biochemical techniques, the interphotoreceptor retinoid-binding protein (IRBP), cellular retinal-binding protein (CRALBP), and cellular retinol-binding protein (CRBP) will be examined in the following retinal degenerations: 1) mouse mutants including retinal degeneration (rd), nervous (nr), Purkinje cell degeneration (pcd) and retinal degeneration slow (rds); 2) dog retinal degenerations including rod-cone dysplasia in the Irish setter, rod dysplasia with cone degeneration in the Norwegian elkhound and progressive rod-cone dysplasia in the poodle; 3) photoreceptor degeneration induced by constant light in the albino rat; and 4) human retinal diseases. These retinal degenerations differ in their time course and in the cause of photoreceptor degeneration. In the proposed study it will be possible to compare the effects of different types of retinal degenerations on the retinoid-binding proteins and to determine if any similarities exist between human retinal degenerations and these known animal models. The retinoid-binding proteins will also be studied in developing normal mouse and dog retinas. The normal mouse will be a control for the mouse mutants and will provide new knowledge about retinoid-binding proteins in a rod dominated retina. The dog similarly will serve as a control for the canine mutants as well as an example of normal development in a duplex retina.